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Old 2008-09-14, 10:53   #12
davieddy
 
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Are we discussing one of the spinoffs advantageous to mankind here?

Last fiddled with by davieddy on 2008-09-14 at 11:02
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Old 2008-09-14, 13:16   #13
bsquared
 
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Quote:
Originally Posted by cheesehead View Post

"How long would it take the LHC to defrost a pizza?"
But can it improve on this?
http://www.youtube.com/watch?v=TBLr_XrooLs
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Old 2008-09-14, 20:21   #14
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Originally Posted by KriZp View Post
It doesn't say anything about the duration of the energy release, only the power. 10 TW. Does it lasts as long as their calculated defrost time?
The defrost time would be the total of however-many beam pulses it takes, I presume.

I frequently find it handy to recall that the speed of light is approximately one foot (~30 cm) per nanosecond. So, during the pizza-defrosting time of 30 nanoseconds, the beam could travel a maximum of about 30 feet (9 meters) (measured in the presumably-at-rest pizza's reference frame). If one assumes that a beam pulse length would be equal to the circumference of the LHC ring, then even without looking it up, I confidently guess that's a lot longer than 30 feet (9 meters). Of course, a beam pulse doesn't [I]have[/I] to be that (LHC circumference) long, either.

Edit: Wait! ... I just found some actual figures... will extend posting in a few minutes.

In a paper (http://ieeexplore.ieee.org/iel5/1060...1/01591808.pdf) from the Proceedings of 2005 Particle Accelerator Conference, Knoxville, Tennessee, on page 4321 (believe it or not) we find:
Quote:
The LHC ion beam is composed of bunches with rms [root-mean-square] duration of 250 ps [picoseconds], separated by 100 ns.
That means that the bunches (apparently the official terminology, instead of my "pulses") occupy only 0.25% of the length of the interval between bunches.

Thus, the pizza-defrost time of 30 nanoseconds would require 30 ns / 0.25 ns per bunch = 120 bunches, taking an elapsed time of 120 x 100 ns = 12 microseconds.
Quote:
Originally Posted by retina View Post
A more relevant question is how many pizzas can LHC defrost each second.
Maximum throughput would be less than 84,000 pizza-defrostings per second.

Note, however, that in order to move pizzas in and out of the LHC beam at rates approaching 84,000 pizza-defrostings per second would require that each pizza move in excess of a speed of at least (84,000 x pizza diameter) per second for some part or all of its travel, thus requiring that the appropriate relativistic corrections be applied to the not-at-rest-as-previously-presumed pizza's frame-of-reference. These might extend the defrosting time as measured in the presumably-at-rest LHC staff's frame-of-reference, further reducing achievable throughput!

OTOH, air friction might significantly contribute energy to each pizza, perhaps partially compensating for the relativistic differences in reference frames. Quantitative evaluation of this effect is beyond the scope of the current posting. :-(

Last fiddled with by cheesehead on 2008-09-14 at 21:21
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Old 2008-09-14, 20:57   #15
cheesehead
 
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Quote:
Originally Posted by davieddy View Post
Are we discussing one of the spinoffs advantageous to mankind here?
No. It probably wouldn't be a good idea to eat an LHC-cooked pizza after its bombardment by all those ions. (And ... what if the pizza came out with a black hole lodged in it?)

Besides, DiGiorno's lawyers would probably say that using an LHC ion beam, instead of a microwave oven, voids the warranty.

Last fiddled with by cheesehead on 2008-09-14 at 21:04
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Old 2008-09-14, 21:27   #16
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Originally Posted by cheesehead View Post
No. It probably wouldn't be a good idea to eat an LHC-cooked pizza after its bombardment by all those ions. (And ... what if the pizza came out with a black hole lodged in it?)

Besides, DiGiorno's lawyers would probably say that using an LHC ion beam, instead of a microwave oven, voids the warranty.
What exactly would the ion beam do to the pizza that would make it not edible?
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Old 2008-09-14, 21:35   #17
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What exactly would the ion beam do to the pizza that would make it not edible?
Besides the imbedded-black-hole possibility?

The energetic particles (at those speeds and energies, the exact nature of the beam particles, whether ionized or not and so forth, really wouldn't matter) would, undoubtedly, disrupt quite a few molecular bonds (possibly changing an edible or benign molecule into something toxic), render some nuclei radioactive by changing their proton/neutron counts, and maybe even transmute some nuclei into toxic elements (even if nonradioactive).

Warning: Vegetarians may wish to skip the following paragraph.

It's one thing to irradiate ground beef with gamma rays of frequencies known not to make toxic changes to anything other than bacteria (i.e., bacterial DNA is disrupted, killing and preventing them from multiplying, but disrupted beef DNA wouldn't kill already-dead beef -- your digestive system's going to disrupt any eaten DNA anyway, but you don't want to ingest toxins excreted by still-living bacteria), but quite another thing to bombard with the much-higher energies of the LHC beam.

Last fiddled with by cheesehead on 2008-09-14 at 21:43
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Old 2008-09-14, 21:59   #18
Flatlander
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Quote:
Originally Posted by cheesehead View Post
... (And ... what if the pizza came out with a black hole lodged in it?)
I always thought they were olives?
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Old 2008-09-14, 22:17   #19
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Quote:
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(And ... what if the pizza came out with a black hole lodged in it?)
Worst cavities ever.

Alex
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Old 2008-09-15, 02:09   #20
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(And ... what if the pizza came out with a black hole lodged in it?)
Well if Swiss cheese has holes in it, why not their pizza?

As the LHC is now officially rated at 84K PDs (Pizza Defrostings) what would the PD rating have been if they built the unit in Texas?
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Old 2008-09-15, 02:25   #21
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Worst cavities ever
You sound like my dentist.

Last fiddled with by Wacky on 2008-09-15 at 02:26
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Old 2008-09-15, 02:32   #22
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Quote:
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What would the PD rating have been if they built the unit in Texas?
Above or below 40º C? Before, or after "Ike"?

It's difficult to keep workstations/servers on line when the power grid fails for weeks.
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